title: Environmental enrichment and social interaction improve cognitive function and decrease reactive oxidative species in normal adult mice.
abstract: Environmental stimulation and increased social interactions stimulate cognitive performance, while decrease in these parameters can exacerbate cognitive decline as a function of illness, injury, or age. We examined the impact of environmental stimulation and social interactions on cognitive performance in healthy adult C57B1/6J mice. Mice were housed for 1 month individually or in groups of three (to prevent or allow social interaction) in either a standard environment (SE) or an enlarged cage containing nesting material and items classically utilized to stimulate exploration and activity ("enriched environment"; EE). Cognitive performance was tested by Y maze navigation and Novel Object Recognition (NOR; which compares the relative amount of time mice spent investigating a novel vs. a familiar object). Mice maintained for 1 month under isolated conditions in the SE statistically declined in performance versus baseline in the Y maze (p < 0.02; ANOVA). Performance under all other conditions did not change from baseline. Maintenance in groups in the SE statistically improved NOR (p < 0.01), whereas maintenance in isolation in the SE did not alter performance from baseline. Maintenance in the EE statistically improved performance in NOR for mice housed in groups and individually (p < 0.01). Maintenance under isolated conditions slightly increased reactive oxygen/nitrogen species (ROS/RNS) in brain. Environmental enrichment did not influence ROS/RNS. These findings indicate that environmental and social enrichment can positively influence cognitive performance in healthy adult mice, and support the notion that proactive approaches may delay age-related cognitive decline.
authors.affiliation: Center for Cellular Neurobiology and Neurodegeneration Research, Department of Biological Sciences, University of Massachusetts Lowell , Lowell, MA , USA.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Doulames
authors.forename: Sangmook
authors.initials: S
authors.lastname: Lee
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Shea
mesh_terms: D000818:Animals; D003071:Cognition / Q000502:physiology*; D004777:Environment; D005106:Exploratory Behavior / Q000502:physiology; D005260:Female; D007398:Interpersonal Relations; D018782:Maze Learning / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D011597:Psychomotor Performance / Q000502:physiology; D017382:Reactive Oxygen Species / Q000378:metabolism*; D021641:Recognition, Psychology / Q000502:physiology
chemical_list: D017382:Reactive Oxygen Species